For this purpose you will need a good screen. 1080p should be the min to look for and make sure that it has 95% or more sRGB color coverage. If you don't know what this is then you can just make sure it is a 1080p ips screen with wide viewing angles.
For the other specs, you don't need much.
I would recommend an i5 - 4500/6500u depending on the amount of battery life you want.
4 gigs min, 8 max.
And ssd for fast booting and opening times of programs. The size will be up to you.
No dedicated gpu needed.
The os will be up to you.